Conventionally, as an example of a transmission system that enables transmission and reception of contents data between a plurality of transmission terminals via a relay device, there is a known teleconference system for conducting a teleconference via a communication network, such as the Internet.
In the teleconference system, when the contents data, such as video or audio, is transmitted and received, the contents data is encrypted to ensure the security of the contents data. As a method for encrypting the contents data, for example, secure real-time transport protocol (SRTP) (RFC 3711) or the like is known.
As the method for encrypting the contents data, for example, Japanese Translation of PCT international application publication No. 2010-531562 discloses a technology, in which a packet to be encrypted is selected from a plurality of packets of digital video contents according to a selection criterion and the selected packet is encrypted in order to form selectively-encrypted digital video contents.
However, encryption and decryption processes in the transmission system greatly consume hardware resources of the transmission system. This reduces the real time performance in a communication of the contents data and causes video loss or audio jumping.
The present invention has been made in view of the above, and an object thereof is to provide a transmission management apparatus, a program, a transmission management system, and a transmission management method capable of realizing high-quality data transmission while ensuring the security of data transmitted and received by a transmission system.